The invention relates to a method for controlling an automated, non-synchromesh multispeed motor vehicle transmission and a control device of an automated, non-synchromesh multispeed transmission of a motor vehicle, for controlling the engagement of a target gear via a shift operator.
EP 0 161 521 A1 describes a method for controlling an automated, non-synchromesh multispeed transmission of a motor vehicle. In the method an engagement of a target gear is aborted if a predetermined period of time has elapsed since the process of engagement commenced, without being able to complete the engagement. In this case the transmission is brought into a neutral position.
In order to engage a gear in a non-synchromesh multispeed transmission, a positively interlocking connection must be established between gear-shifting elements of the target gear, such as a loose gear and a gearshift sleeve, through displacement of the gearshift sleeve. The loose gear is thereby torsionally locked to a shaft of the transmission. Since a non-synchromesh multispeed transmission does not have synchromesh devices for each gear, a gear can be engaged only when no great speed differential prevails between the gear-shifting elements, since otherwise the claws of the loose gear cannot mesh with the claws of the gearshift sleeve. The gearshift sleeve is engaged by a gearshift actuator pressing it against the loose gear, so that a contact is established between the claws. If meshing is impossible due to the speed differential between the gear-shifting elements, the claws repel one another against the force of the gearshift actuator, which can cause damage to the claws and hence to the multispeed transmission. This repulsion is referred to as so-called chattering.
It is the object of the present invention to provide a method for controlling, and a control device of, an automated non-synchromesh multispeed motor vehicle transmission which will prevent the multi-speed transmission being damaged during engagement of a target gear.